From what I understand, the stains of the alaya vijnana are always there until Buddhahood, even during the realization of shunyata during the journey through the bhumis. There are many teachings going into depth on how the teachings work at this level.

It's possible to experience memories without any sense of personal identity attached to them even at a moderate level of practice experience.

Kye ma!
The river of continuity is marked by impermanence.
Ceaseless flowing of appearance.
Beautiful and repulsive.
The dance of life and death is a display of the vast expanse.
With gratitude the watcher and the watched pass through the barrier of duality.